Peroxycarboxylic acids are known for use as antimicrobials and bleaching agents. Mixed peroxycarboxylic acid systems are also known for use as antimicrobial and bleaching agents. However, there are disadvantages to use of these antimicrobial and bleaching agents. For example, the most commonly used peroxycarboxylic acid, peroxyacetic acid, is known to have a strong pungent odor. In addition, peracids such as peroxycarboxylic acid have known chemical disadvantages, namely, they are relatively unstable in solution and decompose to the corresponding carboxylic acids and oxygen.
Conventional peroxycarboxylic acid compositions are made through an acid catalyzed equilibrium reaction. Most often, the peroxycarboxylic acids are generated in a chemical plant, and then shipped to customers for on-site use. Due to the limited storage stability of peroxycarboxylic acids, the peroxycarboxylic acids must be packed in special containers and shipped under the strict Department of Transportation (DOT) guidelines. Certain improvements to peroxycarboxylic acid stability have proved advantageous for shipping purposes, as described in U.S. patent application Ser. No. 11/847,604, entitled “Shelf Stable, Reduced Corrosion, Ready to Use Peroxycarboxylic Acid Antimicrobial Compositions,” the entire contents of which are hereby expressly incorporated herein by reference. Most commercially available products in an equilibrium mixture contain excess hydrogen peroxide in the presence of stabilizers and acid catalysts, to stabilize and improve the composition's shelf life. Despite such stability improvements, excess amounts of reagents (e.g., acids, oxidizing agents, and stabilizers) are present in the compositions during shipping to prevent decomposition. These and other disadvantages to the use of peracid compositions exist.
Accordingly, it is an objective of the claimed invention to develop in situ methods for generation of peroxycarboxylic acids at alkaline pH.
A further object of the invention is an in situ method for generation of stable single peracid systems that are substantially free of stabilizing agents and/or surfactants.
A further object of the invention is an in situ method for generation of stable mixed peracid systems that are substantially free of stabilizing agents and/or surfactants.
A still further object of the invention is to develop concentrated peracid chemistries for further dilution and/or use on site within a matter of hours to days in order to eliminate the need for various stabilizing agents in the compositions to ensure storage stability (e.g. stability for at least one year as required for regulated chemistries).